Unable to open any .mp4 files – “Apple could not verify file is free of malware”
Hi everyone,
I am facing an issue on my Mac where I am unable to open any video files with the .mp4 extension.
Whenever I try to open an MP4 file, I get the following error message:
“Apple could not verify ‘[filename].mp4’ is free of malware that may harm your Mac or compromise your privacy.”
Because of this, the file does not open at all.
Key points:
- This is happening for all MP4 files (not just one specific file)
- Files are downloaded from trusted sources
- Even newly downloaded files are showing the same error
- I am unable to play videos using default apps or even after installing VLC
System details:
- Mac model: [MacBook Air m4]
- macOS version: [macOS Tahoe - 26.4]
What I want to understand:
- Why is macOS blocking MP4 files like this?
- Is this a Gatekeeper or security setting issue?
- How can I safely allow and open these files without compromising security?
- Is there any permanent fix so this doesn’t happen for every file?
Would really appreciate guidance on resolving this issue.
Thanks in advance!
Best regards,
Aashok *****
[Edited by Moderator]
MacBook Air 13″, macOS 26.4
